Linux-AIO/AIO.xs

#include "EXTERN.h"
#include "perl.h"
#include "XSUB.h"

#include <sys/types.h>
#include <unistd.h>
#include <fcntl.h>
#include <sched.h>

#define STACKSIZE 1024 /* yeah */

#define REQ_QUIT  0
#define REQ_READ  1
#define REQ_WRITE 2

typedef struct {
  char stack[STACKSIZE];
} aio_thread;

typedef struct {
  int type;
  aio_thread *thread;

/* read/write */
  int fd;
  off_t offset;
  size_t length;
  ssize_t result;
  int errorno;

  SV *data, *callback;
  void *dataptr;
  STRLEN dataoffset;
} aio_cb;

typedef aio_cb *aio_req;

static int started;
static int nreqs;
static int reqpipe[2], respipe[2];

static int aio_proc(void *arg);

static void
start_thread(void)
{
  aio_thread *thr;

  New (0, thr, 1, aio_thread);

  if (clone (aio_proc,
             &(thr->stack[STACKSIZE]),
             CLONE_VM|CLONE_FS|CLONE_FILES|CLONE_SIGHAND,
             thr) >= 0)
    started++;
  else
    Safefree (thr);
}

static void
end_thread(void)
{
  aio_req req;
  New (0, req, 1, aio_cb);
  req->type = REQ_QUIT;
  write (reqpipe[1], &req, sizeof (aio_req));
}

static void
read_write (pTHX_ int dowrite, int fd, off_t offset, size_t length,
            SV *data, STRLEN dataoffset, SV*callback)
{
  aio_req req;
  STRLEN svlen;
  char *svptr = SvPV (data, svlen);

  if (dataoffset < 0)
    dataoffset += svlen;

  if (dataoffset < 0 || dataoffset > svlen)
    croak ("data offset outside of string");

  if (dowrite)
    {
      /* write: check length and adjust. */
      if (length < 0 || length + dataoffset > svlen)
        length = svlen - dataoffset;
    }
  else
    {
      /* read: grow scalar as necessary */
      svptr = SvGROW (data, length + dataoffset);
    }

  if (length < 0)
    croak ("length must not be negative");

  New (0, req, 1, aio_cb);

  if (!req)
    croak ("out of memory during aio_req allocation");

  req->type = dowrite ? REQ_WRITE : REQ_READ;
  req->fd = fd;
  req->offset = offset;
  req->length = length;
  req->data = SvREFCNT_inc (data);
  req->dataptr = svptr + dataoffset;
  req->callback = SvREFCNT_inc (callback);

  nreqs++;
  write (reqpipe[1], &req, sizeof (aio_req));
}

static int
poll_cb (pTHX)
{
  dSP;
  int count = 0;
  aio_req req;

  while (read (respipe[0], (void *)&req, sizeof (req)) == sizeof (req))
    {
      if (req->type == REQ_QUIT)
        {
          Safefree (req->thread);
          started--;
        }
      else
        {
          int errorno = errno;
          errno = req->errorno;

          if (req->type == REQ_READ)
            SvCUR_set (req->data, req->result > 0
                                  ? req->dataoffset + req->result
                                  : req->dataoffset);

          PUSHMARK (SP);
          XPUSHs (sv_2mortal (newSViv (req->result)));
          PUTBACK;
          call_sv (req->callback, G_VOID);
          SPAGAIN;
          
          SvREFCNT_dec (req->data);
          SvREFCNT_dec (req->callback);

          errno = errorno;
          nreqs--;
          count++;
        }

      Safefree (req);
    }

  return count;
}

#undef errno
#include <asm/unistd.h>

static int
aio_proc(void *thr_arg)
{
  aio_thread *thr = thr_arg;
  int sig;
  int errno;
  aio_req req;

  /* we rely on gcc's ability to create closures. */
  _syscall3(int,lseek,int,fd,off_t,offset,int,whence);
  _syscall3(int,read,int,fd,char *,buf,off_t,count);
  _syscall3(int,write,int,fd,char *,buf,off_t,count);

  /* first get rid of any signals */
  for (sig = 1; sig < _NSIG; sig++)
    signal (sig, SIG_DFL);

  signal (SIGPIPE, SIG_IGN);
 
  /* then loop */
  while (read (reqpipe[0], (void *)&req, sizeof (req)) == sizeof (req))
    {
      req->thread = thr;

      if (req->type == REQ_READ || req->type == REQ_WRITE)
        {
          errno = 0;

          if (lseek (req->fd, req->offset, SEEK_SET) == req->offset)
            {
              if (req->type == REQ_READ)
                req->result = read (req->fd, req->dataptr, req->length);
              else
                req->result = write(req->fd, req->dataptr, req->length);
            }

          req->errorno = errno;
        }
      else
        {
          write (respipe[1], (void *)&req, sizeof (req));
          break;
        }

      write (respipe[1], (void *)&req, sizeof (req));
    }

  return 0;
}

MODULE = Linux::AIO                PACKAGE = Linux::AIO

BOOT:
{
        if (pipe (reqpipe) || pipe (respipe))
          croak ("unable to initialize request or result pipe");

        if (fcntl (respipe[0], F_SETFL, O_NONBLOCK))
          croak ("cannot set result pipe to nonblocking mode");
}

void
min_parallel(nthreads)
        int     nthreads
        PROTOTYPE: $
        CODE:
        while (nthreads > started)
          start_thread ();

void
max_parallel(nthreads)
        int     nthreads
        PROTOTYPE: $
        CODE:
        int cur = started;
        while (cur > nthreads)
          {          
            end_thread ();
            cur--;
          }

        poll_cb ();
        while (started > nthreads)
          {
            sched_yield ();
            poll_cb ();
          }

void
aio_read(fh,offset,length,data,dataoffset,callback)
        PerlIO *        fh
        unsigned long   offset
        long            length
        SV *            data
        STRLEN          dataoffset
        SV *            callback
        PROTOTYPE: $$$$$$
        ALIAS:
          aio_write = 1
        CODE:
        sv_upgrade (data, SVt_PV);
        read_write (aTHX_ ix, PerlIO_fileno (fh), offset, length, data, dataoffset, callback);

int
poll_fileno()
        PROTOTYPE:
        CODE:
        RETVAL = respipe[0];
        OUTPUT:
        RETVAL

int
poll_cb()
        PROTOTYPE:
        CODE:
        RETVAL = poll_cb (aTHX);
        OUTPUT:
        RETVAL

int
nreqs()
        PROTOTYPE:
        CODE:
        RETVAL = nreqs;
        OUTPUT:
        RETVAL

Revision:	1.5
Committed:	Tue Aug 14 18:06:37 2001 UTC (22 years, 9 months ago) by root
Branch:	MAIN
Changes since 1.4:	+148 -11 lines
Log Message:	* empty log message *
#	User	Rev	Content
1	root	1.1	#include "EXTERN.h"
2			#include "perl.h"
3			#include "XSUB.h"
4
5			#include <sys/types.h>
6			#include <unistd.h>
7	root	1.5	#include <fcntl.h>
8	root	1.1	#include <sched.h>
9
10	root	1.5	#define STACKSIZE 1024 /* yeah */
11	root	1.1
12	root	1.2	#define REQ_QUIT 0
13	root	1.1	#define REQ_READ 1
14			#define REQ_WRITE 2
15
16			typedef struct {
17			char stack[STACKSIZE];
18			} aio_thread;
19
20			typedef struct {
21			int type;
22			aio_thread *thread;
23
24			/* read/write */
25			int fd;
26			off_t offset;
27			size_t length;
28	root	1.2	ssize_t result;
29	root	1.1	int errorno;
30
31	root	1.5	SV data, callback;
32	root	1.1	void *dataptr;
33	root	1.2	STRLEN dataoffset;
34	root	1.1	} aio_cb;
35
36			typedef aio_cb *aio_req;
37
38			static int started;
39	root	1.5	static int nreqs;
40	root	1.1	static int reqpipe[2], respipe[2];
41
42	root	1.2	static int aio_proc(void *arg);
43
44	root	1.1	static void
45			start_thread(void)
46			{
47	root	1.2	aio_thread *thr;
48
49			New (0, thr, 1, aio_thread);
50
51			if (clone (aio_proc,
52			&(thr->stack[STACKSIZE]),
53			CLONE_VM\|CLONE_FS\|CLONE_FILES\|CLONE_SIGHAND,
54			thr) >= 0)
55			started++;
56			else
57			Safefree (thr);
58	root	1.1	}
59
60			static void
61			end_thread(void)
62			{
63	root	1.5	aio_req req;
64			New (0, req, 1, aio_cb);
65			req->type = REQ_QUIT;
66	root	1.1	write (reqpipe[1], &req, sizeof (aio_req));
67	root	1.2	}
68
69			static void
70	root	1.5	read_write (pTHX_ int dowrite, int fd, off_t offset, size_t length,
71			SV data, STRLEN dataoffset, SVcallback)
72	root	1.2	{
73	root	1.5	aio_req req;
74			STRLEN svlen;
75			char *svptr = SvPV (data, svlen);
76
77			if (dataoffset < 0)
78			dataoffset += svlen;
79
80			if (dataoffset < 0 \|\| dataoffset > svlen)
81			croak ("data offset outside of string");
82
83			if (dowrite)
84			{
85			/* write: check length and adjust. */
86			if (length < 0 \|\| length + dataoffset > svlen)
87			length = svlen - dataoffset;
88			}
89			else
90			{
91			/* read: grow scalar as necessary */
92			svptr = SvGROW (data, length + dataoffset);
93			}
94
95			if (length < 0)
96			croak ("length must not be negative");
97
98			New (0, req, 1, aio_cb);
99
100			if (!req)
101			croak ("out of memory during aio_req allocation");
102
103			req->type = dowrite ? REQ_WRITE : REQ_READ;
104			req->fd = fd;
105			req->offset = offset;
106			req->length = length;
107			req->data = SvREFCNT_inc (data);
108			req->dataptr = svptr + dataoffset;
109			req->callback = SvREFCNT_inc (callback);
110
111			nreqs++;
112			write (reqpipe[1], &req, sizeof (aio_req));
113			}
114
115			static int
116			poll_cb (pTHX)
117			{
118			dSP;
119			int count = 0;
120			aio_req req;
121
122			while (read (respipe[0], (void *)&req, sizeof (req)) == sizeof (req))
123			{
124			if (req->type == REQ_QUIT)
125			{
126			Safefree (req->thread);
127			started--;
128			}
129			else
130			{
131			int errorno = errno;
132			errno = req->errorno;
133
134			if (req->type == REQ_READ)
135			SvCUR_set (req->data, req->result > 0
136			? req->dataoffset + req->result
137			: req->dataoffset);
138
139			PUSHMARK (SP);
140			XPUSHs (sv_2mortal (newSViv (req->result)));
141			PUTBACK;
142			call_sv (req->callback, G_VOID);
143			SPAGAIN;
144
145			SvREFCNT_dec (req->data);
146			SvREFCNT_dec (req->callback);
147
148			errno = errorno;
149			nreqs--;
150			count++;
151			}
152
153			Safefree (req);
154			}
155
156			return count;
157	root	1.2	}
158
159			#undef errno
160			#include <asm/unistd.h>
161
162			static int
163			aio_proc(void *thr_arg)
164			{
165			aio_thread *thr = thr_arg;
166			int sig;
167			int errno;
168			aio_req req;
169
170			/* we rely on gcc's ability to create closures. */
171			_syscall3(int,lseek,int,fd,off_t,offset,int,whence);
172			_syscall3(int,read,int,fd,char *,buf,off_t,count);
173			_syscall3(int,write,int,fd,char *,buf,off_t,count);
174
175			/* first get rid of any signals */
176			for (sig = 1; sig < _NSIG; sig++)
177	root	1.5	signal (sig, SIG_DFL);
178	root	1.4
179	root	1.5	signal (SIGPIPE, SIG_IGN);
180	root	1.2
181			/* then loop */
182			while (read (reqpipe[0], (void *)&req, sizeof (req)) == sizeof (req))
183			{
184			req->thread = thr;
185
186			if (req->type == REQ_READ \|\| req->type == REQ_WRITE)
187			{
188			errno = 0;
189
190			if (lseek (req->fd, req->offset, SEEK_SET) == req->offset)
191			{
192			if (req->type == REQ_READ)
193			req->result = read (req->fd, req->dataptr, req->length);
194			else
195			req->result = write(req->fd, req->dataptr, req->length);
196			}
197
198			req->errorno = errno;
199			}
200			else
201			{
202			write (respipe[1], (void *)&req, sizeof (req));
203			break;
204			}
205
206			write (respipe[1], (void *)&req, sizeof (req));
207			}
208
209			return 0;
210	root	1.1	}
211
212			MODULE = Linux::AIO PACKAGE = Linux::AIO
213
214			BOOT:
215			{
216			if (pipe (reqpipe) \|\| pipe (respipe))
217			croak ("unable to initialize request or result pipe");
218	root	1.5
219			if (fcntl (respipe[0], F_SETFL, O_NONBLOCK))
220			croak ("cannot set result pipe to nonblocking mode");
221	root	1.1	}
222
223			void
224			min_parallel(nthreads)
225			int nthreads
226	root	1.5	PROTOTYPE: $
227	root	1.1	CODE:
228			while (nthreads > started)
229			start_thread ();
230
231			void
232			max_parallel(nthreads)
233			int nthreads
234	root	1.5	PROTOTYPE: $
235	root	1.1	CODE:
236	root	1.5	int cur = started;
237			while (cur > nthreads)
238			{
239			end_thread ();
240			cur--;
241			}
242
243			poll_cb ();
244	root	1.1	while (started > nthreads)
245	root	1.5	{
246			sched_yield ();
247			poll_cb ();
248			}
249	root	1.1
250			void
251	root	1.5	aio_read(fh,offset,length,data,dataoffset,callback)
252			PerlIO * fh
253			unsigned long offset
254			long length
255			SV * data
256			STRLEN dataoffset
257			SV * callback
258			PROTOTYPE: $$$$$$
259	root	1.3	ALIAS:
260	root	1.5	aio_write = 1
261	root	1.1	CODE:
262	root	1.5	sv_upgrade (data, SVt_PV);
263			read_write (aTHX_ ix, PerlIO_fileno (fh), offset, length, data, dataoffset, callback);
264
265			int
266			poll_fileno()
267			PROTOTYPE:
268			CODE:
269			RETVAL = respipe[0];
270			OUTPUT:
271			RETVAL
272
273			int
274			poll_cb()
275			PROTOTYPE:
276			CODE:
277			RETVAL = poll_cb (aTHX);
278			OUTPUT:
279			RETVAL
280
281			int
282			nreqs()
283			PROTOTYPE:
284			CODE:
285			RETVAL = nreqs;
286			OUTPUT:
287			RETVAL
288